A composite camshaft has a shaft and a plurality of fitting members such as cams and journals separately fabricated and fixedly mounted on the shaft. The journal is generally made of a sinterable alloy material or ordinary steel. The journal of sinterable alloy is diffusion-bonded to the shaft by a liquid-phase sintering, having no problem in connection with a binding strength between the journal and the shaft. On the other hand, the journal of ordinary steel is bonded to the shaft by brazing.
The brazing method has been disclosed by JP A No. 56-109908 and JP A No. 57-81953, having the steps of putting a brazing material on one side of the bore of the fitting member and melting it by heat. However, there is no assurance that the brazing material will reach the opposite side of the fitting member.
The present invention is intended to resolve the problem as described above and provide a composite camshaft and a method of making the same in which a journal is firmly bonded to a shaft by a brazing material which penetrates through a clearance between the journal and the shaft.